Electric hand tool, in particular drill

ABSTRACT

In an electric hand tool, particularly a drill, with a housing, an electric motor which is received in the housing and has a motor shaft parallel to the housing axis, and with a work spindle which is driven by the electric motor via a transmission gearing, the housing is divided along a dividing plane for the purpose of switching from straight drilling to angular drilling and it is provided that the front housing part containing a bearing for the work spindle and the rear housing part containing the electric motor can swivel relative to one another in such a way that the work spindle projecting out of the front housing part can occupy any angle between 0° and 90° or more relative to the motor shaft. A catch lock which can be unlocked and/or locked manually stops the two housing parts in the selected swivel position. A torsionally rigid transmission of force from the motor shaft to the work spindle is realized in every swivel position of the housing parts in the transmission gearing.

BACKGROUND OF THE INVENTION

The present invention relates to an electric hand tool, particularly adrill.

More particularly, it relates to an electric hand tool which has ahousing, an electric motor accommodated in the housing and having amotor shaft, and a work spindle driven by the electric motor via atransmission gearing and carrying a tool receptacle.

Drills of this type are usually constructed as straight-drillingmachines in which the drill spindle extends parallel to the motor shaftand axis of the housing and, for specific purposes, as angular-drillingmachines in which the drill spindle is aligned at a right angle to themotor shaft and housing axis. In certain applications in which bothstraight and angular drilling must be carried out, as is the case ininstallations in American wooden house construction, the two machinesmust be at hand for continuous alternation.

A tool receptacle head serving as special accessory for a conventionaldrill is already known from DE 36 34 734 A1. It includes two separatehousing parts having a hollow space which are located opposite oneanother and guided along a diagonally extending dividing plane. Onehousing part carries a support for a drive shaft and the other housingpart carries a support for a power take-off shaft which projects out ofthe tool receptacle head and carries a drill chuck. The drive shaft andpower take-off shaft are connected with one another by a double cardanor universal joint so as to be rigid with respect to torsion relative toone another. One hollow-cylindrical housing part of the tool receptaclehead is placed on the spindle neck of the drill and the drill spindle ofthe drill is coupled with a driver by means of a double edge. The driversits on the drive shaft so as to be fixed with respect to rotationrelative to it. In the basic position of the two housing parts, the axesof the drive and power take-off shafts are flush with one another. Dueto the relative rotation of the two housing parts, the power take-offshaft can be aligned in such a way that its axis encloses an acute orright angle with the axis of the drive shaft.

A standard drill can be re-tooled with this known tool receptacle headso as to form an angle drill which can also perform straight drilling.

While such a separate tool receptacle head serving as attachment iswell-suited to the requirements of the home worker, it is not acceptablefor professional machines.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide anelectric hand tool, particularly a drill of the above mentioned type,which avoids the disadvantages of the prior art.

In keeping with these objects and with others which will become apparenthereinafter, one feature of the present invention resides, brieflystated, in an electric hand tool of the above type in which inaccordance with the present invention the housing is divided along adividing plane so that the front housing part which contains a bearingfor the work spindle and a rear housing part which contains the electricmotor can rotate relative to one another in such a way that the workspindle projecting in the front housing part can occupy any anglebetween 0° and 90° or more relative to the motor shaft and the housingaxis, a catch lock can be unlocked and locked manually for stopping thehousing parts in a selected swivel position, and a torsionally rigidtransmission of force from the motor shaft to the electric motor to thework spindle is realized in the transmission gearing in every swivelposition of the housing parts.

When the electric hand tool is designed in accordance with the presentinvention, it; has the advantage of being a compact, convenient electrictool for professional requirements which at first glance does not differfrom a standard electric tool, but in contrast to the latter allows anangular position of the work spindle relative to the motor shaft andhousing axis between 0° and 90° (flush and at a right angle). Thiselectric tool can be used for both straight and angular drilling andalso enables diagonal bore holes.

The work spindle can be manually switched quickly and easily by a catchlock so that it is possible to work with different angular positions ofthe work spindle in repetitive sequence. A rigid torsion-prooftransmission of force is provided in every position of the work spindleso that transmission faults do not occur. The higher cost of thetransmission gearing in comparison with a standard electric tool isoffset in part by taking advantage of the gearing space for larger gearwheel diameters and a complete gearing step can be dispensed with as aresult of the greater transmission ratio made possible by this.

In a preferred embodiment form of the invention the transmission gearingis constructed as a double bevel gear unit whose first bevel gear sitson an intermediate shaft so as to be fixed with respect to rotationrelative to it, the intermediate shaft being supported in the housing,and meshes with a first bevel pinion which is supported on the motorshaft so as to be fixed with respect to rotation relative to it andwhose second bevel gear sits on the work spindle so as to be fixed withrespect to rotation relative to it and meshes with a second bevel pinionwhich is rigidly attached to the intermediate shaft. A rotating rimwhose rotational axis encloses an angle of 90° or 45° relative to theaxis of the motor shaft is arranged in the dividing plane between thetwo housing parts. The advantage of the latter version consists in thatthe corner dimension, i.e. the distance of the work spindle from theforemost housing edge, is substantially smaller in the angular drillingposition.

In a first embodiment form of the invention the transmission gearing isconstructed as a spur gear unit whose power take-off shaft is connectedvia a double-jointed drive or universal shaft with the work spindle soas to be fixed with respect to rotation relative to it. The work spindleand the power take-off shaft of the spur gear unit are arranged so as tobe offset relative to one another in such a way that the axis of theuniversal shaft coincides with the rotational axis of the rotating rimand encloses an axial angle of 45° with the axes of the motor shaft andwork spindle in the basic position and in the 90-degree swivel positionof the two housing parts. The axis of rotation of the rotating rimsituated in the dividing plane between the two housing parts encloses anangle of 45° with the axis of the motor shaft and the joint of theuniversal shaft on the work spindle side is situated approximately inthe dividing plane. This construction has the particular advantage thatextremely small corner dimensions can be realized for the 0-degree and90-degree positions of the work spindle. However, a disadvantage to betaken into account consists in that speed errors occur in theintermediate positions of the work spindle since there is nocompensation of the transmission errors of the universal joints.

In a construction of the embodiment form of the invention anintermediate flange is arranged in the region of the dividing planebetween the two housing parts, which intermediate flange is rotatablysupported at the front housing part and is connected with the rearhousing part so as to be fixed with respect to rotation relative to it.The dividing plane is situated in such a way that the axis of rotationof the intermediate flange encloses a right angle with the motor shaft.The intermediate flange is preferably clamped in between two axialbearings arranged one behind the other in the axial direction. One axialbearing is supported at the front housing part and the other axialbearing is supported at a clamping plate which is screwed to the fronthousing part. The intermediate flange which is rotatable relative to thefront housing part is sealed relative to the latter by an O-ring. Theconstructional unit which includes the intermediate flange, axialbearings and clamping plate and is securely connected with the fronthousing part is inserted into the rear housing part and the intermediateflange is fastened to it by screws. In this way the intermediate flangeis rotatably mounted at the front housing part so as to be virtuallyfree of play and the gap between the two mutually rotatable housingparts is accordingly very small. Accordingly, a seal is achieved whichon the whole has low friction and is tight against dust. The drill canbe assembled very simply and quickly as a result of the constructionalunit preassembled on the front housing part.

FIG. 1 shows a side view of an electric hand drill, partially insection;

FIG. 2 shows a section through part of the drill in FIG. 1 with drillspindle swiveled for angular drilling;

FIG. 3 is a schematic view of a longitudinal section through part of adrill according to another embodiment example;

FIG. 4 shows a section according to line IV--IV in FIG. 3;

FIG. 5 shows the same view as in FIG. 5 with the drill spindle rotatedby 90° for angular drilling;

FIGS. 6 and 7 show schematic longitudinal sections through part of adrill according to a third embodiment example in the "straight drilling"position (FIG. 6) and "angular drilling" position (FIG. 7);

FIGS. 8 and 9 are schematic longitudinal sections through part of adrill according to a fourth embodiment example in the "straightdrilling" position (FIG. 8) and "angular drilling" position (FIG. 9);

FIGS. 10 and 11 are schematic side views of a part of a drill accordingto a fifth embodiment example in the "straight drilling" position (FIG.10) and "angular drilling" position (FIG. 11);

FIGS. 12 and 13 show a perspective view of part of a drill with a catchlock for the rotating housing part;

FIG. 14 shows a longitudinal section through part of a drill accordingto a sixth embodiment example;

FIG. 15 shows a top view of the drill as seen in the direction of arrowXV in FIG. 14;

FIG. 16 shows a section along line XVI--XVI in FIG. 15.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The electric hand drill shown in partial section in FIG. 1 as an examplefor an electric hand tool has a housing 10 on which a handle 11 with agrip opening 12 is formed in one piece. The connection cable isdesignated by 13 and the switch strip for switching the drill on and offis designated by 14.

An electric motor 15 whose motor shaft 16 extends along the housing axisis received in a known manner in the housing 10. The motor shaft 16drives a drill spindle 18 via a transmission gearing 17. The drillspindle 18 is rotatably supported in a bearing 19 of the housing 10 andprojects out of the housing 10. The drill spindle 18 carries a drillchuck 20 at its free end projecting out of the housing 10 for clamping adrill bit.

The housing 10 is divided along a dividing plane, designated by 21, intoa front housing part 101 containing the bearing 19 for the drill spindle18 and into a rear housing part 102 which receives the motor 15 withmotor shaft 16. The dividing plane is situated at an angle of 45°relative to the axis of the motor shaft 16 and the housing axis,respectively. A rotating rim 22 whose axis of rotation is verticalrelative to the dividing plane 21 is arranged in the dividing plane 21between the two housing parts 101 and 102. The rotating rim 22 has twoannular grooves 23, 24 which are inserted into the front and rearhousing part 101, 102, respectively. The front housing part 101 overlapsthe rear housing part 102 in the region of the dividing plane 21 in sucha way that the two annular grooves 23, 24 which are triangular in crosssection are situated one on above the other in a mirror-inverted mannerin the dividing plane 21 and form an annular duct which is filled withballs 25. For the purpose of filling the annular duct 23, 24 with theballs 25 a filling bore hole (not shown) is inserted in the fronthousing part 101 from the outside. The filling bore hole opens into theannular groove 23 and has a bore hole diameter which is greater than theball diameter. The balls 25 are inserted into the annular duct formedfrom the annular grooves 23, 24 through this filling bore hole. Thefilling bore hole is then closed.

The transmission gearing 17 between the motor shaft 16 and the drillspindle 18 which extends parallel to the motor shaft 16, but so as to beoffset relative to it, in the basic position shown in FIG. 1 isconstructed as a double bevel gear unit. The first bevel gear 26 sits onan intermediate shaft 27 so as to be fixed with respect to rotationrelative to it, the intermediate shaft 27 being supported in the housing10, and meshes with a first bevel pinion 28 which sits on the motorshaft 16 so as to be fixed with respect to rotation relative to it. Thesecond bevel gear 29 of the second gearing step sits on the drillspindle 18 so as to be fixed with respect to rotation relative to it andmeshes with a second bevel pinion 30 which is constructed on theintermediate shaft 27. The axis of the intermediate shaft 27 coincideswith the axis of rotation of the rotating rim 22.

When the front housing part 101 is turned relative to the rear housingpart 102, the second bevel gear 29 wanders around the axis of rotationof the rotating cross 22 while remaining always engaged with the secondbevel pinion 30 so that force is transmitted from the motor shaft 16 tothe drill spindle 18 in a torsionally rigid manner in every swivelposition of the front housing part 101 via the transmission gearing 17.FIG. 2 shows the 90-degree swivel position of the front housing part101. The drill spindle 18 is at a right angle to the motor shaft 16 andcan carry out angular drilling with the drill. The minimum cornerdimension E, i.e. the distance of the axis of the drill spindle 18 fromthe foremost housing edge, is determined in this construction of thebevel gear unit 17 with axial angles of 45° by the diameter of thesecond bevel gear 29 and can accordingly be kept very small in anadvantageous manner. The two housing parts 101, 102 are locked togetherso as to be fixed with respect to rotation relative to one another inevery angular position between 0° and 90° by a catch lock to bedescribed in the following, so that the drill forms an easily handledrigid unit.

The drill, sections of which are shown in FIGS. 3 to 5, likewise has atransmission gearing 17 constructed as a bevel gear unit. As shown bythe longitudinal section in FIG. 3, the dividing plane 21 between thefront housing part 101 and the rear housing part 102 is situatedparallel to the axis of the motor shaft 16 and the housing axis so thatthe rotational axis of the rotating rim 22 arranged in the dividingplane is at a right angle to the axis of the motor shaft 16. The bevelgear unit 17 is constructed with axial angles of 90° corresponding tothis position of the dividing plane 21. The axis of the intermediateshaft 27 is in turn flush with the rotational axis of the rotating rim22. FIG. 4 shows a sectional view of the drill according to sectionIV--IV in FIG. 3. The front housing part 101 is in its 0° basic positionand the drill can be used for straight drilling. By turning the fronthousing part 101 in the rotating rim 22, the drill spindle 18 can beadjusted to every desired angle between 0° and 90° relative to the motorshaft 16. The 90-degree rotating position is shown in FIG. 5. As canclearly be seen, the minimum corner dimension E is determined by thefirst bevel gear 26 and is accordingly greater than in the drill shownin FIGS. 1 and 2.

As in the drill shown in FIGS. 1 and 2, the front housing part 101 canbe stopped in any swivel position between 0° and 90° by a catch lock atthe rear housing part 102. An example for such a catch lock 31 is shownschematically in the angular drill according to FIG. 12 or in theangular drill according to FIG. 13. In both cases the catch lock 31,which includes a rim 32 with a plurality of grooves 33 arranged atequidistant intervals and a locking pin 34, catches in one of thegrooves 33 under the influence of the spring tension of a pressurespring 35. In the embodiment example in FIG. 12, the rim 32 with grooves33 is fastened parallel to the dividing plane 21 in the rear housingpart 102. The locking pin 34 is formed by a leg of a locking angle 36extending vertically relative to the dividing plane 21, the other legextending radially and projecting outward through a bore hole 37 in thefront housing part 101. The second leg of the locking angle 36 carries aknob 38 at the end. The pressure spring 35, which is constructed as ahelical spring and concentrically surrounds this leg, is supported atthe knob 38 and at the housing wall of the front housing part 101 andaccordingly presses the locking pin 34 into one of the grooves 33 of therim 32. To adjust a different swivel position of the drill spindle 18with the drill chuck 20 the locking angle 36 is radially displaced inthe bore hole 37 by applying force to the knob 38 so that the lockingpin 34 leaves the groove 33. After the new angular position of the drillspindle 18 is adjusted by turning the front housing part 101, the knob38 is released again and the pressure spring 35 pushes the locking pin34 back into the corresponding groove 33.

The catch lock 31 in the drill according to FIG. 13 is modified only inthat the rim 32 with grooves 33 is fastened in the front housing part101 parallel to the dividing plane 21 and the locking angle 36 withlocking pin 34 is guided so as to be axially displaceable in a bore hole37 in the rear housing part 102. For the rest, the construction andoperation are identical.

In the drill according to FIGS. 6 and 7, the dividing plane 21 issituated between the front housing part 101 and the rear housing part102 at an angle of 45° relative to the axis of the motor shaft 16 andhousing axis, respectively. The transmission gear unit 17 is constructedas a double spur gear unit whose power take-off shaft 40 is connectedwith the drill spindle 18 via a double-jointed universal shaft 41 so asto be rigid against torsion. The double spur gear unit 17 has a firstspur gear 42 which sits on an intermediate shaft 43 supported in thehousing 10 so as to be fixed with respect to rotation relative to it andmeshes with a first drive pinion 44 sitting on the motor shaft 16 so asto be fixed with respect to rotation relative to it and a second spurgear 45 which is connected with the intermediate shaft 43 so as to befixed with respect to rotation relative to it and meshes with a seconddrive pinion 46 which is constructed at the intermediate shaft 43. Thetorsionally rigid connection between the universal shaft 41 and thepower take-off shaft 40 is produced by a first universal joint 48 andthe torsionally rigid connection between the universal shaft 41 and thedrill spindle 18 is produced by a second universal joint 47. The drillspindle 18 and the power take-off shaft 40 of the spur gear unit 17 arearranged so as to be offset relative to one another in such a way thatthe axis of the universal shaft 41 coincides with the rotational axis ofthe rotating rim 22 in the dividing plane 21 and encloses an axial angleof 45° with the axes of the motor shaft 16 and drill spindle 18 in the0-degree basic position (FIG. 6) and in the 90-degree swivel position(FIG. 7) of the two housing parts 101, 102. The universal joint 47 ofthe universal shaft 41 on the work spindle side is situated in or in thevicinity of the dividing plane 21. As can be seen from FIGS. 6 and 7,the universal shaft 41 is accordingly guided in a Z-shaped manner instraight drilling operation and angularly in angular drilling operationand the transmission errors of the universal joints 47, 48 arecompensated for in these two positions by the axial angle of 45°. Thisconstruction has the particular advantage that extremely small cornerdimensions E can be realized for both positions shown in FIGS. 6 and 7.However, the fact must be taken into account that transmission errors ofthe universal joints 47, 48 are not compensated for in the intermediatepositions of the drill spindle 18 between the 0-degree and 90-degreeswivel positions and speed errors occur. This drill is thereforeconstructed exclusively with only these two swivel positions of thedrill spindle 18, namely 0° and 90°.

The drill which is shown schematically in part in FIGS. 8 and 9 inlongitudinal section is largely identical with the drill according toFIGS. 6 and 7 with the exception that the universal shaft 41 is notguided in a Z-shaped manner in the 0-degree basic position of the fronthousing part 101, i.e. in the "straight drilling" position, but ratheris stretched and is flush with the drill spindle 18 and the powertake-off shaft 40 of the transmission gearing 17 which is likewiseconstructed as a double spur gear unit. The dividing plane 21 issituated approximately in the center of the universal shaft 41. Theuniversal shaft 41 is also outfitted with length compensating means 49which makes it possible to lengthen or shorten the universal shaft 41when rotating the front housing part 101. In contrast to the drillaccording to FIGS. 6 and 7, the corner dimension E cannot be madeoptionally small in straight drilling operation, since it is defined bythe first spur gear 42 of the double spur gear unit 17 and thearrangement of the second spur gear 45 is predetermined by the centralposition of the drill spindle 18.

In the drill shown in part in FIGS. 10 and 11 in a side view, thehousing 10 is divided along another dividing plane 21' and theintermediate housing 103 which is accordingly formed is connected withthe front housing part 101 and with the rear housing part 102 via arotating rim (not shown) which is arranged in the dividing plane 21 or21'. The dividing planes 21, 21' and the two rotating rims situatedtherein are arranged in such a way that the axes of the rotating rimsenclose an angle of 22.5° with the housing axes of the front housingpart 101 and rear housing part 102 and intersect at an angle of 45°. Therotational axes of the two rotating rims are designated by 51 and 52 inFIG. 10. The front housing part 101 and the rear housing part 102 areconnected with one another so as to be fixed with respect to rotationvia a guide, not shown, so that they cannot rotate relative to oneanother. The transmission gearing of the drill, not shown here, is againconstructed as a double spur gear unit whose power take-off shaft isdesignated by 40. The power take-off shaft 40 and drill spindle 18 areagain connected with the two universal joints 47, 48 so as to be rigidwith respect to torsion via a universal shaft 41. The articulationpoints of the universal joints 47, 48 lie in dividing planes 21, 21',respectively. If this is dispensed with, the universal shaft 41 must beprovided with length compensating means.

The intermediate housing 103 is rotated in order to swivel the drillspindle 18. The drill spindle 18 can be swiveled into any desired swivelposition relative to the housing axis of the rear housing part 102 andcan be locked in the swivel position. FIG. 11 shows the 90-degreeposition of the drill spindle 18 for angular drilling. In this drill, asin the drill according to FIGS. 8 and 9, the corner dimension E instraight drilling is defined by the first spur gear. The arrangement ofthe second spur gear of the second gear unit stage is predetermined bythe position of the drill spindle 18 and can have only a limiteddiameter if a small corner dimension is desired. An additional gearingstep may be required under certain conditions to achieve a sufficienttotal transmission ratio.

The construction of a drill shown in part in FIGS. 14 to 16 conforms tothat of the angle drill in FIGS. 3 to 5 with respect to the position ofthe dividing plane 21 between the front and rear housing parts 101, 102and the construction of the transmission gearing 17 as a double bevelgear unit with axial angles of 90°. However, in this instance therotating rim is replaced by an intermediate flange 60 which is rotatablymounted at the front housing part 101 in the region of the dividingplane 21 and is connected with the rear housing part 102 so as to befixed with respect to rotation relative to it. The rotational axis ofthe intermediate flange 60 occupies an angle of 90° relative to the axisof the motor shaft 16. In order to mount the intermediate flange 60 atthe front housing part 101 in a rotatable manner, the intermediateflange 60 is clamped between two axial bearings 61, 62 which are placedtogether with the intermediate flange 60 and a supporting plate 63 on ahollow receiving sleeve 64 which is connected with the front housingpart 101. A clamping plate 65 is securely screwed to the front side ofthe receiving sleeve 64 by threaded screws, designated by 66, and has acentral bore hole 67 exposing the clear opening of the receiving sleeve64. The axial length of the receiving sleeve 64 is dimensioned in such away that the supporting plate 63 contacts a stop shoulder 68 constructedon the front housing part 101 at the base of the receiving sleeve 64 andthe axial bearing 61 is supported between this supporting plate 63 andthe intermediate flange 60, and the axial bearing 62 is supportedbetween the intermediate flange 60 and the clamping plate 65. Theintermediate flange 60 has a somewhat cap-shaped construction andcarries a groove 69 in the end face of its thickened edge area 601facing the front housing part 101, which groove 69 receives a sealingring 70 contacting the front housing part 101. The sealing ring 70 isarranged in such a way that it does not obstruct or hinder the relativerotation between the front housing part 101 and the intermediate flange60 so that the intermediate flange 60 can be turned easily by handrelative to the front housing part 101. The play occurring in thedividing plane 21 during relative rotation between the front housingpart 101 and the intermediate flange 60 is extremely small due to theclamping of the intermediate flange 60 between the two axial bearings61, 62, and the gap between the front housing part 101 and intermediateflange 60 is sealed so as to be reliably tight against dust via thesealing ring 70 in every rotating position of the front housing part101.

The front housing part 101 with the constructional unit attached to itand including the intermediate flange 60, axial bearings 61, 62 andclamping plate 65 is placed on the pot-shaped rear housing part 101 inthis region in an exact fit. The rear housing part 102 engages in acircumferential fitting groove at 71 with an annular projection. Thereceiving sleeve 64 overlaps the front part of the intermediate shaft 27of the transmission gearing 17 supported in the rear housing part 102with play approximately up to the first bevel gear 26 which sits on theintermediate shaft 27 so as to be fixed with respect to rotationrelative to it and meshes with the first bevel pinion 28 which isconnected with the motor shaft 16 so as to be fixed with respect torotation relative to it. At the conclusion of the attaching movement ofthe front housing part 101 with the intermediate flange 60, the secondbevel pinion 30 constructed at the free end of the intermediate shaft 27engages with the second bevel gear 29 sitting on the drill spindle 18 soas to be fixed with respect to rotation relative to it. The drillspindle 18 with the drill chuck 20 fastened to it is received in thefront housing part 101 so as to be rotatable via a ball bearing 19 and aroller bearing 19'. After the front housing part 101 is placed on therear housing part 102 the intermediate flange 60 is fixed at the rearhousing part 102 by screws 72 (FIG. 15). The front housing part 101 isaccordingly fastened to the rear housing part 102 in the dividing plane21 so as to be rotatable. As indicated in FIG. 15, the swiveling area ofthe front housing part 101 with the drill spindle 18 is 225°. The drillspindle 18 can thus be swiveled toward both sides up to an angle of112.5° relative to the axis of the motor shaft 16.

In the swiveling area of 225° of the upper housing part 101, a catch isprovided in angular steps of 22.5° in which the upper housing part 101can be rigidly fastened at the lower housing part 102. A catch lock 31",shown in FIGS. 15 and 16, is provided for this purpose. As in theembodiment example according to FIG. 12, the catch lock 31" includes aring of equidistant catch recesses 73 arranged in angular increments of22.5°, which in this instance is held at the intermediate flange 60 soas to be fixed against rotation, and two locking pins which are held inthe front housing part 101 so as to be radially displaceable. Onelocking pin 74 is shown in FIG. 16. The catch recesses 73 are formeddirectly at the intermediate flange 60. A catch recess 73 is also shownin FIG. 14. Every catch recess 73 is open in the radial direction sothat the locking pins 74 can be slid out of the catch recesses 73 byradial displacement or can engage in them under the influence of springpressure. As can be seen in FIG. 16 for one locking pin 74, the twolocking pins 74 are arranged so as to be radially displaceablediametrically opposite one another at the front housing part 101. Eachlocking pin 74 is formed by the free end of a stirrup 75 (FIG. 16) whichis inserted into a guide 77 in the front housing part 101 so as to slidewith a sliding bar 76 bent at an angle of 90° relative to the lockingpin 74, the guide 77 being aligned transversely relative to the drillspindle 18. A pocket-like receiving bore hole 78 of increased diameterfor an unlocking knob 79 adjoins the guide 77 on the outside. Theunlocking knob 79 is fastened at the free end of the sliding bar 76 andprojects out of the housing contour in the locking position of thelocking pin 74. A cylindrical pressure spring 80 placed on the slidingrod 76 is supported at the base of the receiving bore hole 78 on the onehand and at the unlocking knob 79 on the other hand and thus produces arestoring force which slides the locking pin 74 into the catch recess73. As can be seen from FIG. 15, the two unlocking knobs 79 for the twolocking pins 74 are aligned transversely with respect to the drillspindle 18 and lie so as to be flush with one another at opposite sidesof the housing part 101 in such a way that they can be gripped betweenthe thumb and finger of one hand and moved toward one another. Thismovement unlocks the catch lock 31" and the front housing part 101 canbe moved into a desired swivel position. When this swivel position isachieved the two unlocking knobs 79 are released and the locking pins 74are automatically slid into the diametrically opposite catch recesses 73by the pressure springs 80. The front housing part 101 with drillspindle 18 is again fixed with respect to rotation in the selected newwork position. The construction of the catch lock 31- with two unlockingknobs 79 which are to be actuated simultaneously has the advantage thatan unintentional unlocking of the catch lock 31" while working with thedrill is also not possible when an unlocking knob 79 is pressed in bymistake.

FIG. 14 also shows an adjustable depth stop 81 which is held at the rearhousing part 102. The desired drilling depth can be set with the depthstop 81.

It will be understood that each of the elements described above, or twoor more together, may also find a useful application in other types ofconstructions differing from the types described above.

While the invention has been illustrated and described as embodied in anelectric hand tool, in particular a drill, it is not intended to belimited to the details shown, since various modifications and structuralchanges may be made without departing in any way from the spirit of thepresent invention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can, by applying current knowledge,readily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this invention.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims:
 1. An electric hand tool, comprising ahousing having a housing axis, an electric motor received in saidhousing and having a motor shaft parallel to said housing axis; a workspindle driven by said electric motor and having spindle end projectingout of said housing; a transmission gearing located between saidelectric motor and said work spindle so that said work spindle is drivenby said electric motor via said transmission gearing; a bearing providedfor said work spindle, said housing being divided along a dividing lineinto a front housing part which contains said bearing for said workspindle and a rear housing part which contains said electric motor andare rotatable relative to one another so that said work spindleextending in said front housing part can occupy a plurality of anglesrelative to said motor shaft and said housing axis; a manually operatingcatch lock for stopping said housing parts in a selected angularposition relative to one another, said transmission being formed so thata torsionally rigid transmission of force from said motor shaft of saidelectric motor to said work spindle is provided in said transmissiongearing in every angular position of said housing parts relative to oneanother; an intermediate flange arranged in the region of said dividingplane between said two housing parts and rotatably supported at saidfront housing part and connected with said rear housing part, saiddividing plane being located so that a rotational axis of saidintermediate flange encloses an angle of 90° relative to an axis of saidmotor shaft; a clamping plate which is fastened at said front housingpart; and two axial bearings arranged one after the other in the axialdirection of said intermediate flange and clamping said intermediateflange therebetween, one of said axial bearings being supported in saidfront housing part while another of said axial bearings is supported atsaid clamping plate, said intermediate flange being screwed to said rearhousing part.
 2. An electric tool as defined in claim 1, wherein saidwork spindle is rotatably supported in said housing and carries a toolreceptacle at said end projecting out of said housing.
 3. An electrictool as defined in claim 1; and further comprising means for sealingsaid intermediate flange relative to said front housing part.
 4. Anelectric tool as defined in claim 3 wherein said sealing means includesa sealing ring arranged in said intermediate flange.
 5. An electric toolas defined in claim 3, wherein said intermediate flange tightly contactssaid rear housing part.
 6. An electric tool as defined in claim 1,wherein said front housing part with said work spindle is swivelablerelative to said rear housing part by 22.5° and is lockable in angularincrements of 22.5°.
 7. An electric hand tool, comprising a housinghaving a housing axis, an electric motor received in said housing andhaving a motor shaft parallel to said housing axis; a work spindledriven by said electric motor and having spindle end projecting out ofsaid housing; a transmission gearing located between said electric motorand said work spindle so that said work spindle is driven by saidelectric motor via said transmission gearing; a bearing provided forsaid work spindle, said housing being divided along a dividing line intoa front housing part which contains said bearing for said work spindleand a rear housing part which contains said electric motor and arerotatable relative to one another so that said work spindle extending insaid front housing part can occupy a plurality of angles relative tosaid motor shaft and said housing axis; a manually operating catch lockfor stopping said housing parts in a selected angular position relativeto one another, said transmission being formed so that a torsionallyrigid transmission of force from said motor shaft of said electric motorto said work spindle is provided in said transmission gearing in everyangular position of said housing parts relative to one another; anintermediate flange arranged in the region of said dividing planebetween said two housing parts and rotatably supported at said fronthousing part and connected with said rear housing part, said dividingplane being located so that a rotational axis of said intermediateflange encloses an angle of 90° relative to an axis of said motor shaft,said catch lock having a ring of catch recesses arranged at equidistantintervals and is held at said intermediate flange so as to be fixed withrespect to rotation, and two locking pins supported so as to be radiallydisplaceable in said front housing part, engage in diametricallyopposite ones of said catch recesses, and are displaceable against aspring force, two unlocking knobs via which said two locking pins aredisplaceable at opposite sides of said front housing part and which arealigned with one another transversely to said work spindle for liftingout of said catch recesses, said unlocking knobs being arranged at saidfront housing part so that they can be gripped between a thumb andfinger of one hand for a displacing movement in opposite directions.